Derksen A C, Granados R R
Boyce Thompson Institute for Plant Research at Cornell University, Ithaca, New York 14853.
Virology. 1988 Nov;167(1):242-50. doi: 10.1016/0042-6822(88)90074-8.
The peritrophic membrane (PM), which lines the midgut of many insect species, has several functions. In particular, it may serve as a mechanical barrier to invading microorganisms. The protein composition of the PM from healthy and baculovirus-treated Trichoplusia ni (cabbage looper) larvae was analyzed by polyacrylamide gel electrophoresis. A specific interaction took place between baculoviruses and the PM of susceptible T. ni larvae. A 68-kDa glycoprotein of the PM disappeared within 15 min postinoculation with occlusion bodies of either Autographa californica nuclear polyhedrosis virus (AcMNPV) or T. ni nuclear polyhedrosis virus (TnSNPV). In contrast, inoculation of larvae with a T. ni granulosis virus (TnGV) resulted in the disappearance of three distinct major glycoproteins with molecular weights of 253, 194, and 123 kDa. PMs of virus-treated larvae were very fragile compared with those of untreated controls, indicative of a physical/chemical change in their structure. T. ni larval bioassays showed that a factor, present in the TnGV granulin or AcMNPV polyhedrin, enhanced the infectivity of AcMNPV. These data showed that a factor present in the occlusion bodies of three distinct baculoviruses can cause specific biochemical and structural changes in the PM. The biological significance of these observations in relation to increased larval infection is not known at this time.
围食膜（PM）衬于许多昆虫物种的中肠，具有多种功能。特别是，它可能作为抵御入侵微生物的机械屏障。通过聚丙烯酰胺凝胶电泳分析了健康的和经杆状病毒处理的粉纹夜蛾（甘蓝夜蛾）幼虫围食膜的蛋白质组成。杆状病毒与易感粉纹夜蛾幼虫的围食膜之间发生了特异性相互作用。用苜蓿银纹夜蛾核型多角体病毒（AcMNPV）或粉纹夜蛾核型多角体病毒（TnSNPV）的包涵体接种后15分钟内，围食膜的一种68 kDa糖蛋白消失。相比之下，用粉纹夜蛾颗粒体病毒（TnGV）接种幼虫导致三种分子量分别为253、194和123 kDa的不同主要糖蛋白消失。与未处理的对照相比，经病毒处理的幼虫的围食膜非常脆弱，这表明其结构发生了物理/化学变化。粉纹夜蛾幼虫生物测定表明，TnGV颗粒蛋白或AcMNPV多角体蛋白中存在的一种因子增强了AcMNPV的感染性。这些数据表明，三种不同杆状病毒的包涵体中存在的一种因子可导致围食膜发生特定的生化和结构变化。目前尚不清楚这些观察结果与幼虫感染增加相关的生物学意义。
